Lighting unit with multiple light sources of a different color temperature

Abstract

In a lighting unit for operating lamps (LA 1 , LA 2 ) of a different color temperature, a number of predetermined color points can be adjusted. The color points are chosen so that the color difference calculated in the CIELAB space is the same for subsequent adjustable color points.

1. A lighting unit, comprising:
 at least two light sources of a different color temperature; 
 an operating circuit, comprising:
 a supply circuit for supplying currents to the two light sources, and 
 a control circuit for controlling the currents supplied by the supply circuit; and a user interface coupled to the control circuit for adjusting the color of the generated light at a number of predetermined color settings by means of adjusting the light outputs of the light sources,
 wherein the color difference calculated in the CIELAB color space between a first color point corresponding to a first color setting and a nearest color point corresponding to a second color setting is the same for any first color point having the same value of the total light output, and 
 wherein the user interface comprises:
 a first push button for adjusting the color of the generated light at the predetermined color setting having the next higher value of the color temperature at every push and 
 a second push button for adjusting the color of the generated light at the predetermined color setting having the next lower value of the color temperature at every push. 
 
 
 
 
   
   
     2. A lighting unit as claimed in  claim 1 , wherein the user interface further comprises means for adjusting the total light output of the lighting unit at a number of predetermined levels via the control circuit. 
   
   
     3. A lighting unit as claimed in  claim 2 , wherein the color difference calculated in the CIELAB space between color points corresponding to the same color setting and to successive levels of total light output is the same for each level of the total light output. 
   
   
     4. A lighting unit as claimed in  claim 1 , wherein the user interface further comprises:
 a third push button for adjusting the total light output of the generated light at the next higher level at every push and 
 a fourth push button for adjusting the total light output of the generated light at the next lower level at every push. 
 
   
   
     5. A lighting unit as claimed in  claim 1 , wherein the user interface further comprises a diamond-shaped surface comprising a number of adjustment points for facilitating a user action and wherein adjacent adjustment points in a first direction correspond to the same level of the total light output and to different color settings and adjacent adjustment points in a second direction correspond to the same color setting and different levels of total light output. 
   
   
     6. A lighting unit as claimed in  claim 5 , wherein the adjustment points are formed by push buttons. 
   
   
     7. A lighting unit as claimed in  claim 5 , wherein the diamond shaped surface is formed by a touch pad. 
   
   
     8. A lighting unit as claimed in  claim 5 , wherein the diamond shaped surface is equipped with a mapping of the adjustable colors. 
   
   
     9. A lighting unit, comprising:
 at least two light sources of a different color temperature; 
 an operating circuit, comprising
 a supply circuit for supplying currents to the two light sources, 
 a control circuit for controlling the currents supplied by the supply circuit, and 
 
 a user interface coupled to the control circuit for adjusting the color of the generated light at a number of predetermined color settings by means of adjusting the light outputs of the light sources,
 wherein the color difference calculated in the CIELAB color space between a first color point corresponding to a first color setting and a nearest color point corresponding to a second color setting is the same for any first color point having the same value of total light output, 
 wherein the user interface comprises a diamond-shaped surface comprising a number of adjustment points for facilitating a user action, and 
 wherein adjacent adjustment points in a first direction correspond to the same level of the total light output and to different color settings and adjacent adjustment points in a second direction correspond to the same color setting and different levels of total light output. 
 
 
   
   
     10. A lighting unit as claimed in  claim 9 , wherein the adjustment points are formed by push buttons. 
   
   
     11. A lighting unit as claimed in  claim 9 , wherein the diamond-shaped surface is formed by a touch pad. 
   
   
     12. A lighting unit as claimed in  claim 9 , wherein the diamond-shaped surface is equipped with a mapping of the adjustable colors.